


Show Me Your Teeth

by wordbending



Series: Undyne Appreciation Week [3]
Category: Undertale (Video Game)
Genre: Alphyne-Centric, F/F, Trans Alphys, Trans Female Character, Undyne appreciation week, mildly nsfw, there's some makeouts here but nothing too explicit, trans undyne
Language: English
Status: Completed
Published: 2017-07-20
Updated: 2017-07-20
Packaged: 2018-12-04 12:12:02
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,623
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11554959
Author URL: https://archiveofourown.org/users/wordbending/pseuds/wordbending
Summary: Undyne and Alphys make out. Alphys chews on an idea.For Day Three ofUndyne Appreciation Week: Undyne's big, toothy smile.





	Show Me Your Teeth

**Author's Note:**

> I wildly misinterpreted this prompt as being about "Undyne's teeth" instead of "Undyne's smile" and by the time I realized it, I was too attached to this idea to not do it.
> 
> Hope you have a fetish for shark teeth!

Alphys started to tug her shirt over her head.

“W-w-wait!” Undyne shouted, covering her eyes. Her blue skin started to turn a light shade of green.

“Undyne,” Alphys said flatly, putting her shirt back down. “T-that’s c-c-cute and all, b-b-but it’s not like you haven’t s-seen them before.”

“No, I mean, just...” Undyne said, lowering her hands but decidedly looking away. “I don’t want to, like, rush things this time, you know. Can’t we just... um... snuggle?”

Alphys barely repressed a giggle, covering her snout with her claws. Her yellow tail wagged back and forth slowly.

“It’s even c-c-cuter hearing you say ‘s-snuggle’,” Alphys teased. She scooted closer, so that she was face-to-face with Undyne, their torsos a few inches apart.

Undyne swallowed, her face still that shade of green. Alphys felt suddenly... unsure about what she was doing. Undyne could be shy, but she was acting kind of weird about this.

“H-h-hey, Undyne?”

Undyne gave an awkward smile.

“Yeah, Alphys?”

“Are you... OK? W-with this? If you... if you don’t want to...” Alphys blushed. “You know. I’d u-u-understand. We can just w-watch anime.”

Rapidly, Undyne shook her head and raised her hands in front of herself. Alphys didn’t know what that meant, but Undyne started to speak, very rapidly. “No! No, I want to... I want to...”

Undyne covered her face in her hands, turning even greener.

“K-kiss you.” Her voice was muffled. “And snuggle with you. And do... stuff. I want to really bad, Alphy.”

Alphys nodded. “OK. But t-t-tell me if I’m... making you, um, un-uncomfortable. OK?”

Undyne nodded and, gently, Alphys laid herself down on top of Undyne’s chest. Undyne blushed deeper as Alphys stared up at her with a small, shy smile on her face and her hands under her chin. Her tail continued to wag.

Undyne still looked on edge and was refusing to look at Alphys, even though Alphys was fully clothed. Alphys raised a hand and caressed Undyne’s cheek, which as it usually did, seemed to relax her, to reassure her that it was just her, just her girlfriend who loved her.

Undyne looked down at Alphys and, slowly, a toothy grin started to form on her face.

“I-I...” Alphys said, blinking as she stared at Undyne’s smile.

Undyne’s brow raised.

“Huh?”

Alphys shook her head. “Have I... e-ever told your s-s-smile is... really nice?”

Undyne grinned again, wider this time. “Oh yeah? Thanks!”

Alphys scooted even closer to her, her hand still on Undyne’s cheek. And then she got closer, and even closer, so that she was at eye-level with Undyne’s teeth. She looked closely at the sharp, uneven fangs, all criss-crossed together at parallel angles. Undyne’s teeth were like yellow-white daggers, long enough (and most likely sharp enough) that a bite from her could probably pierce through someone’s arm.

Inexplicably to her, Alphys blushed. She became aware she was staring at them, which made Undyne blink.

“Uhhhh...”

“Oh, s-s-sorry,” Alphys said, backing away from Undyne’s mouth. “I, um, I was just... admiring your, uh, your...”

Alphys heard Undyne repress a snicker.

“D-dental work,” Alphys finished lamely. “Um. Anyway!”

Undyne’s grin widened eagerly.

“Kiss time?”

“Kiss time.”

Alphys took her glasses off and set them, clumsily since she didn’t want to turn her head to look and see what she was doing, on the nearby nightstand. Undyne leaned forward, wrapping her arms around Alphys’ back, and pulled Alphys in. Alphys jumped, a little startled even though she knew it was coming, but she relaxed, letting herself slink across Undyne’s lithe, muscular body. They could only be so close, with Alphys’ weight, but Undyne was always reassuring her that she loved Alphys' body, so Alphys didn’t let that bother her.

Undyne’s lips slid across hers, just barely, before pulling away, in what was a very chaste kiss. But Undyne came back with another, and another, and it was only moments before Alphys was planting some right back at her. Their kissing became increasingly less and less chaste, until there were no pauses between each kiss, until Undyne’s hands were in Alphys’ neck frill and Alphys’ were around Undyne’s head and they were pulled as tightly to each other as physics allowed.

Alphys loved kissing Undyne. She didn’t have a lot of experience with kissing, and their first kisses – real kisses – had been awkward and clumsy, as if either of them were afraid that kissing too hard would cause them both to literally die of embarrassment. But now that they had months, years, under their belt... every kiss with her rapidly devolved into something out of a particular genre of anime. If Undyne was still shy and hesistant at all, Alphys was not – she’d learned what Undyne liked and didn’t hesitate to go for it.

Alphys stopped planting kisses on Undyne’s neck for a moment and just sat there against her chest, watching her breathe. Undyne was a gorgeous woman – as someone else who was trans, she’d always admired Undyne’s effortless beauty, her confidence in herself. It’d taken years, and a lot of Undyne’s reassurance, for Alphys to start to feel as comfortable in her own skin as Undyne did.

But, watching Undyne breathe in and out, her breaths heavy and labored but her grin wide, Alphys couldn’t help but notice something else – Undyne’s sharp, sharp teeth.

And she suddenly had an awful, awful idea. She turned an extremely dark shade of red, and Undyne’s brow creased in concern.

“Whoa, you OK?” she said, sitting up. “What’s up?”

“N-n-nothing!” Alphys squeaked, raising her hands in front of herself. She glanced away, rubbing the back of her head. “I w-was just... I just... had a thought.”

Undyne’s grin widened. She seemed to understand what she meant, which made Alphys feel even _more_ humiliated.

“Oh yeah?” said Undyne cockily. “Hit me.”

Alphys buried her face in her hands, turning redder and redder by the second. She groaned into her hands, suddenly deeply regretting where this conversation was going.

“C-c-could you kiss me again?” she managed to ask, taking her hands away from her mouth but keeping them over her eyes.

“Yeah, sure,” Undyne said, sounding mildly confused. Alphys felt as Undyne gently took her hands by the wrist and pushed them downwards, out of the way of her face. Once her lips could be reached, Alphys felt as Undyne pressed her own against them, starting to kiss her – she started to kiss back, wrapping her arms around Undyne’s torso.

Alphys broke the kiss for a moment.

“OK, OK,” she said, shutting her eyes tightly and taking a deep breath. “C-c-could you... kiss my... k-kiss my...”

Undyne didn’t need her to finish. She started to move down, pressing deep kisses along her jawline, until her lips met the scaly yellow skin of her neck. Undyne started to suck on a scale, which made Alphys shiver.

“Yeah, r-r-right, yeah,” Alphys stammered.

“Anything else?” Undyne said, almost sing-song.

Alphys cringed even harder.

“Oh god.”

“Alphysssss,” she cooed.

“Uh, uh, well,” Alphys tried to say, opening her eyes and looking up towards the ceiling as Undyne continued to press kisses on her neck. She refused to look down at Undyne’s face.

At Undyne’s teeth.

The teeth she could feel in Undyne’s mouth as Undyne kissed her.

“Bite me,” Alphys said suddenly.

Undyne raised her head slightly, narrowing her eye at Alphys. She looked offended.

“Excuse me?”

“No, no, no, no,” Alphys said quickly. “I... I... I m-mean, y-you k-know, uh...”

Alphys paused.

“L-l-literally bite me?”

Alphys dared herself to look down at Undyne, whose head was still right at her neck. At first, Undyne blinked, almost tilting her head. Then, a realization seemed to pass over her, and her face changed. First, it went an extremely dark shade of green, maybe the darkest Alphys had on record. Secondly, her expression broke into a wide, wide, fin-to-fin grin.

Which just made things _worse_. Alphys could see all of her teeth again. Though they were of various sizes and angles, they were each like a mix of a shark and a sabretooth tiger, extremely long and extremely deadly-looking. If Undyne’s muscles weren’t capable of breaking boulders by themselves, Undyne could probably win every single fight she ever fought with her teeth alone.

Alphys swallowed.

“You sure, babe?” Undyne said. Alphys was thrown off-balance by her sudden confidence. She had been expecting Undyne to turn into a flailing mess, and it was only the dark green of Undyne’s normally blue skin that told her that Undyne was trying her damn hardest to accommodate her instead of becoming a big blue ball of nerves. “I don’t want to, you know, hurt you. These things are pretty damn sharp.”

 _God I know,_ thought Alphys before shaking her head to collect her thoughts.

“Just... b-b-be g-gentle, OK?”

Undyne looked mildly anxious, her expression unsure, but she nodded and went back down to Alphys’ neck. She planted a soft, feather-light kiss on one of Alphys’ scales, and Alphys became suddenly extremely aware of how close Undyne’s mouth was to her bare skin.

Undyne opened her mouth wide and Alphys could see all of her teeth, the full length of them. Some of them were inches long and they almost seemed to gleam.

She was going to die. She was literally, actually going to die.

“Yarewwy?” said Undyne, her voice muffled by her mouth hanging open. She looked up at her, still looking unsure what she was doing.

Alphys nodded rapidly. With incredible gentleness, Undyne moved her mouth over Alphys’ neck. Alphys could feel the sharp pinpricks of her teeth, like legendary Japanese samurai swords. Except, you know, poised against her neck.

And then Undyne bit down.

And that was how Alphys ended up in the hospital for three days.


End file.
